Art of deterging



F. W. MUNCIE ART 0F DETERGING sep-t. zo, 193s.

Filed June 27, 1935 4 Sheets-Sheet 1 )WIM/ande Sept. 20, 1938. F. w. MUNclE 2,130,361

ART OF DETERGING Filed June 27, 1935- 4`Shets-Sheet 2 Caz/.mc 600A nfl/rs ral Afl-m39 @www Sept. 20, 1938. Y F. w. MuNclE l 2,130,361

ART OF DETERGING `Filed June 27, 1935 4 Sheets-Sheet 5 n i f l E Sept. 20, 1938. F. w. MuNclE ART OF DETERGING Filed June 2,7. 1955 4 Sheets-Sheet 4 klan Patented Sept. 20, 1938 r"UNITI-:o STATES RT 0F DETERGING Fred Weaver Muncie, New Brunswick, N. J., as-

signor to Colgate-Palmoliv'e-Peet Company, Jersey City, N. J., a corporation of Delaware Application June 27,

11 Claims.

'I'his invention relates to the art of washing or deterging. It concerns particularly, certain new, highly effective detergent materials, their use and an improved process and apparatus whereby these materials may be manufactured speedily and economically, by a continuous process if so desired. The new materials vare far superior to ordinary soaps as detergents in hard water and according to the present invention may be produced at a cost sufficiently low to enable them to compete on a direct price basis with ordinary soap for domestic use.

In a copending application by this inventor, Serial Number 28,712, led June 27, 1935, products of the general type of those adapted to be produced according to this invention are described in detail, and a process is there given by which they may be prepared. The present invention includes a new method for producing an improved variety of the same general type of material and also provides apparatus for accomplishing the preparation of the new products economically and in a continuous manner. The products produced according to the new process are somewhat improved over those produced according to the above mentioned application, although they are apparently of the same general type.

As has been emphasized in the copending application mentioned above, the business of merchandising domestic soaps has become highly competitive, particularly in recent years. To meet this competition many new detergent materials have been produced, most of which are sulphonates or sulphuric acid esters of organic compounds. The sulphonated alcohols are among the better known of these compounds.

While the sulphonated or sulphuric acid ester products heretofore known have certain advantages over ordinary soaps in that they are not al' kaline, do not form insoluble salts with calcium and other metals, and have a high detergent power, nevertheless, such products have not re- -placed ordinary soap for domestic use, primarily because they are too expensive to manufacture.

The purpose of the invention described in the copending application, is to provide a new type of product of this general kind, that is superior to soap in hard water, at a cost crmparable to that of soap, whereby the new product may be sold in direct competition with ordinary soap for domestic use. This will give to the public a much improved detergent product at a price that will encourage the use of the new product despite the keen competition that now exists in the soap merchandising field.

According to the application mentioned, the new products are formed by the interaction of a fatty oil, anhydrous glycerine and fuming sulphuric acid, preferably in the approximate proportion of one molecular weight of fatty oil to 1935, Serial No. 28,711

two molecular weights of glycerlne and in excess of three'molecular Weights of sulphuric acid. Preferably, the resultant product and the excess of sulphuric acid is then neutralized with a concentrated solution of caustic soda or a similar base. In the examples given in that application, the glycerine and fatty oil are first reacted by heating to around 175 to 205 C. in the presence of a small amount of caustic soda or at 280 to 290 C. in the absence of caustic soda. The resultant product is thereafter treated with the'sulphuric acid and finally neutralized.

It has now been found that the preliminary reaction of fatty oil with glycerine is unnecessary. When the three ingredients, in the proportions given, are mixed at a temperature not greatly above room temperature, simultaneously, or in any desired order, an equilibium results with the formation of the same type of product that is produced according to the examples in the copending application. It appears that the sulphuric acid, in the amount and concentration used, acts in a four fold capacity, namely as a hydrolytic agent toward the triglyceride, as an esterifying agent, to sulphate the composition, and for the absorption of the water of reaction. While all of the ingredients may be mixed simultaneously, the preferred mode of reaction is to mix the glycerine and sulphuric acid with cooling and l thereafter combine this mixture, at a slightly elevated temperature, with the fatty oil, since by proceeding in this manner, less darkening is caused by the action of the sulphuric acid on the fatty oil.

This invention, in addition, provides a method by which solutions of the nal neutralized material may be obtained at a concentration that allows the production of dry material economically and in the physical state desired for marketing. In the production of dry material by spraying, for example, a bead of satisfactory size and form is best produced by feeding the material to the spray tower in a concentration of 40% or greater total solids. Neutralization of the material at such concentration is practical only at temperatures above about C. since otherwise the slurry is so stiff that satisfactory mixing and cooling cannot be obtained. However, when an attempt is made to neutralize the material at a suiciently high temperature to make it as uid as is necessary, dificulty is encountered because of decomposition of the product caused by the combination of high acidity or alkalinity and the heat of reaction. To prevent this, according to the present invention, neutralization at high concentration and at relatively high temperatures is accomplished by flowing one or more streams of the acid reaction product and one or more streams of a concentrated neutralizing solution directly into coniiuence, in the exact proportion required for neutralization. This is made practical on a commercial scale by the use of an automatic pH control device to regulate the amount of the neutralizing solution added. 'Ihe result is that the neutralization takes place before the decomposition can be caused and there is then no acidity or alkalinity to further the decomposition.

The neutralization may alternatively be carried out by the addition of slightly less than the proportion of alkali required for complete neutralization, in order to keep the mixture slightly on the acid side until a considerable quantity of material has accumulated, after which the whole may be brought to the exact pH desired. This procedure is sometimes desirable because of the greater resistance of the product to hydrolysis by acid than by alkali.

The mixing of glycerine and sulphuric acid and the reaction of this mixture with fatty oil being simple operations and requiring only a short time of contact, it has been found convenient to conduct the entire process continuously from the initial operation of mixing acid and glycerine tothe drying of the product by spraying or over a heated roll.

In its preferred form, the present invention contemplates the continuous mixing of substantially anhydrous glycerine and fuming sulphuric acid in accurately measured proportions at a controlled temperature and the reacting of the combined acid and glycerine with an accurately measured proportion of fatty oil also at a controlled temperature but which temperature is usually different from that at which the glycerine and acid are mixed, Further, according to the present invention, the mixing of a neutralizing agent with the glycerine-acid-fatty oil product and the control of the amount of neutralizing agent added in accordance with the hydrogen potential (pH) of the final product may all be accomplished continuously. The invention also includes, if desired, the\spray drying of the 'final product to form beads of a pure, white appearance that are readily soluble in either hot or cold water. Alternatively the material may be dried over a heated roll.

While the above process may be considered the preferred embodiment, manufacturing methods and particularly the neutralization step as described in this application may, within the scope of this invention, be applied to making this type of detergent, by the process described in the copending application. Thus a process may be performed according to this invention by continuously mixing the glycerine and fatty oil with caustic soda in accurately controlled proportions, continuously subjecting the mixture to a controlled elevated temperature of around to 205 C. (or around 280 to 290 C. in the absence of caustic soda) to effect the first reaction, thereafter continuously reacting the product with a predetermined proportion of fuming sulphuric acid and subsequently continuously neutralizing as before by passing the product into confluence with the neutralizing agent, the amount of neutralizing agent being controlled by the hydrogen ion potential of the nal product. Alternatively, the reaction product of fatty oil and glycerine made by the batch process may be passed continuously into confluence with the fuming sulphuric acid and subsequently neutralized continuously by passing it into confluence with the neutralizing agent.

If desired, instead of using a continuous process, the new detergents may be made according to the new process of this invention by reacting the fatty oil, glycerine and sulphuric acid in the desired proportions, simultaneously or in any desired order by the batch instead of continuously and the neutralization may also be performed by the batch. In such instances and also in the continuous process, it is preferred to mix the sulphuric acid and glycerine before contacting either with the fatty oil in order to prevent a darkening oi' the oil by the action of the acid. This, however, is not imperative and the reactants may, less desirably, be mixed in a different order.

As a specific example of a process of making the new detergents according to the present invention, 64 pounds of anhydrous glycerine (99.5%) have been mixed with 526 pounds of fuming sulphuric acid (102.8%) at around 30 C. and the mixture stirred with 216 pounds of cocoanut oil at a temperature of 50 C. or slightly less. Fuming sulphuric acid of 102.8% concentration contains about 121/2% excess sulphur trioxide. The reaction completed itself within approximately 40 minutes and the product was thereafter neutralized in the manner above described at a temperature of about 40 C., preferably to a pH of 6.0 to 7.0. If a 30% aqueous solution of caustic soda is used to neutralize the product the resultant solution will contain about 46% total solids of which around 40% will be the organic reaction product, and around 60% sodium sulphate. This combination of organic reaction product and sodium sulphate lfas been found very satisfactory for use as a domestic detergent in place of soap but the percentage of sodium sulphate may be varied by a change in the proportion of sulphuric acid used, or may be remcved entirely, if desired.

In place of 216 pounds of cocoanut oil, given in the above example, 272 pounds of tallow or palm oil may be used, or a mixture of oils may be employed. Glycols may also be substituted for glycerine, due allowance being made for the difference in their molecular weights.

In deciding upon the amount and concentration of sulphuric acid to use in the preparation of the new compounds it has been found that, in general, enough sulphuric acid should be provided to fulfill the molecular weight requirements given above, namely, three molecular weights for every two molecular weights of glycerine and one molecular weight of fatty oil, and in addition there should be an excess of sulphuric acid sumcient to absorb one molecular Weight of Water for each molecular weight of sulphuric Kacid that is to enter the reaction. Since this water needs to be absorbed readily, it is preferable that the amount and concentration of the excess of sulphuric acid be such that after absorbing the water the concentration of the excess sulphuric acid will still be around 99.3%. From this information the amount and concentration of the sulphuric acid, which it is desirable to use, may be readily calculated.

In neutralizing the acid reaction product by flowing the acid and neutralizing material into confluence under closely controlled conditions according to this invention, it has been found possible to use even stronger neutralizing solutions than the 30% caustic soda solution mentioned in the first example and to conduct the neutralization at a temperature considerably in excess of 40 C. This is of advantage for it permits the direct manufacture of more concentrated solutions of the detergent material, from which the final products may be more easily made.'

'I'he solution of the neutralized reaction product may be dried either by the spraying method set forth in United States patent to Dallas R. Lamont No. 1,652,900, or by other well known soap drying methods. The dry material, as made by theV process of the first example, contains around 60% of sodium sulphate and 40% of the organic material and will form a dry, granular, non-hygroscopic powder at room temperature. When warmed somewhat or compounded with an appropriate amount of water, glycerine or mineral oil, it may be milled, plodded or pressed into cakes by the use of the usual soap molding machinery.

As has been said, the sodium sulphate or other sulphate formed by the neutralization can be removed, if desired, but this is not usually necessary, and, in fact, the presence of this inorganic salt in the nal products, in many instances, appears to improve the desirability of the material, particularly for domestic use. 'I'he product made according to the first of the above examples will contain about 60% sodium sulphate. For some purposes, however, it may be desired to produce a detergent according to the present invention but free from the inorganic sulphates formed by the neutralization. To eliminate this sodium sulphate it has been found easier to modify the original process by which the material is produced than to attempt to remove the sodium sulphate, once it has been formed in the composition.

As an example of a process by which the new materials may be formed and freed of inorganic salts, the fatty oil, glycerine and sulphuric acid may be reacted as in the first example above. Then, instead of neutralizing with caustic soda, about 400 pounds of hydrated lime may be added to the mixture as a 10% slurry. Calcium sulphate will be formed from the excess sulphuric acid and lime and will precipitate. The calcium salt of the new detergent product is soluble, however, and the mixture may be filtered to remove the calcium sulphate. Preferably, an amount of water equal to the amount of the solution is used to wash the calcium sulphate free of detergent product. The solution, containing the calcium salt of the new material may then be treated with a solution of sodium carbonate or sodium phosphate or sodium oxalate or other suitable calcium precipitant in an amount slightly in excess of that required to replace all of the calcium in the detergent with sodium and precipitate the calcium as the carbonate, phosphate or oxalate or other insoluble calcium compound. This precipitate may also be filtered oi and the remaining solution is then ready for concentration as desired.

In order to stabilize the new product, the solution may, if it is found necessary, be adjusted to a pH of 6.0 to 7.0. Thereafter, it may be concentrated by boiling until it has the correct solids content for whatever use it is required. The solution may be evaporated to form a solid product from 'a concentration of around`25% or over -by spraying or by the use of drying rolls or by any other suitable method. The anhydrous product when warm is soft and flexible but becomes quite hard and brittle at room temperature and can be prepared as a powder. A 20% aqueous solution of the salt free product is liquid at temperatures above 10 C.

In some instances, it may be desirable to use the calcium salt of the new material directly without converting it into the sodium salt and in other cases it may be to advantage to form the corresponding ammonium, triethanolamine, magnesium, potassium or other salts. These may be formed in the same manner as the sodium salts or ammonia or triethanolamine may be added together with carbon dioxide to precipitate the calcium, instead of adding their carbonates or oxalates, sulphates or phosphates.

The calcium salt may be dried over a heated roll. In this case, a low temperature of drying is desirable, since the product has a tendency to char. The use of vacuum with the roll is desiri able, or the product may be mixed to a slurry with a filler, such as calcium sulphate, chalk, bentonite, pumice or clay and dried by means of the roll.

A product free from inorganic salts may be formed from the product made according to the example, if so desired, by extracting the product with alcohol to remove the product and leave the inorganic salt. Alternatively, the product may be extracted before neutralization, but after sufficient dilution to prevent reaction, with butyl alcohol. The butyl alcohol solution is thereafter neutralized with caustic or the like to the proper pH of around 6.0 to 7.0. Other solvents can be used in place of the alcohol and butyl alcohol mentioned.

In order to aid in the identification of the new products and to demonstrate their effectiveness as detergents certain tests have been performed upon a product made according to the example and containing 60% sodium sulphate, and upon the same product without the sodium sulphate. The sodium sulphate containing product gave 450 cubic centimeters of foam when 50 cubic centimeters of an aqueous solution containing 1% of the material (total solids) were shaken thoroughly in a 500 cubic centimeter closed graduated cylinder. The surface tension of a 0.25% solution was measured as 31.5 dynes per cm. and a 0.125% solution registered 31.8 dynes. The du Nuoy tensionometer was used according to the du Nuoy procedure.

Using a 1% solution of the sulphate containing material (60% sodium sulphate) as solution #l and a 1% solution of the sodium vsulphate free material as solution #2 and adding thereto equal volumes of a number of reagents in 10% solutions and at room temperature, the following results were noted:

Reagent #l #2 l CaCl2.2H1O No precipitate No precipitate. 2 BaC1? White flocculent precipitate. Do. 3 (NFTOQSOl No precipitate Do. 4 l Slight turbidity Slight turbidity. 5 Mgfllzfh No precipitate. No precipitate. 6 13.... do. Do. 7 Pb( (,2H3Om White ilocculent precipitate Do. X CnS04.5H20 No precipitate Do. 9 FeClL .do Do. l0 Zn(`l24 Do. 11 AgNOx Do. l2 HgCl; (saturated). Do. 13 Sea water Do. i4 No turbidity. 15 Hard water (600 ppm.). No turbidity cold or hot. No tlurbidity cold or o . A test was also made of the detergent power of sulphate containing product made according to the example. The standard soil test was used and the following results obtained with a Pulfrich photometer:

Relative detersivo efficiency Product tested Soit water Hard water 50 ppm. 300 ppm.

1 Palm and olive oil soep 100. 0 100. 0 2 Sodium lauryl sulphate. 106. 9 123. 6 3 Sodium oleyl methyl taurina 96. 4 106. 7 4 Present product 111. 5 140. 9

While cocoanut oil has been named in the above examples, it is to be understood that the use of other fatty oils will also result in satisfactory products, due allowance being made for the difference in molecular weights. Among the oils which have been satisfactorily used are tallow, soy bean oil, and palm oil. In fact, it hasl been found that oils ordinarily considered to be inferior for the purpose of making soap, may be used according to this invention to produce products of a very good grade and the use of even such materials as fish oils and garbage grease is within the scope of this invention. Also, glycol or other polyhydric alcohols may be substituted for glycerine and other sulphating or even phosphating compositions may be substituted for sulphuric acid. Monoglycerides may also be formed by reaction with glycerine of fatty acids, naphthenic acids, abietic acid or the carboxylic acids produced by the air oxidation of paraflin hydrocarbons and thereafter reacted with sulphuric acid substantially as indicated above.

The products formed according to this invention are geerally similar in properties to those described in the copending application but show some advantages apparently due to the improvement in the method of their preparation. It has not been possible, however, to explain the improvements in the product on the basis of a change in chemical structure so no new theory of the structure will be here advanced.

It is intended that the present products shall be used directly in place of the ordinary soaps, particularly for laundry, toilet uses and general domestic purposes, but it is possible to use the new products in combination either with the ordinary type of soap or with other types of sulphated or sulphonated detergents or wetting agents. 'I'he new material may be compounded with sodium silicate, talc, pumice, Whiting, feldspar, naphtha, phenols, titanium dioxide,'barium sulphate or other materials commonly incorporated in soap.

The final products may be obtained by suitable manipulation in the form of cakes, powder, flakes or solutions and are adaptable for use as ingredients in shaving, facial or dental creams, liquid shampoos, mouth washes or cleansing solutions, shampoo or dental powders, as an addition to dyestuff baths and for general detergent purposes either alone or in admixture with soap. Since the products are not precipitated by mercury or silver they may also be used to advantage in compounding antiseptic or germicidal detergents with mercury or silver salts. Furthermore, the product has a very much milder taste and odor than ordinary soaps prepared from the same oils and is therefore of particular value in dentifrices or mouth washes. Also, the material is not precipitated by sea water or hard water and hence is particularly valuable where such waters must be used.

Additional details and advantages of the new process and of the apparatus specifically dis- Figure 4 ,is an end view of the apparatus shown in Figure 2;

Figures 5 and 6 are sectional views through the first and second mixers, respectively;

Figures 7 and 8 are sectional views taken on lines 'I-l and 8-8 of Figure 5, respectively;

Figure 9 is a vertical sectional view of the neutralizer; and

Figure 10 is a horizontal sectional view through the neutralizer, taken on line I Il--IU of Figure 9.

The apparatus illustrated in the drawings is a plant installation adapted for the continuous performance of the preferred process of this invention. In describing the operation of this apparatus, reference will be made to sulphuric acid, glycerine, fatty oil or cocoanut oil, and caustic soda. It is to be understood, however, that these are used merely as preferred examples and other equivalent materials or mixtures of materials may be used instead. With this understood, it may be said generally that the apparatus operates, first, to mix the glycerine and the sulphuric acid then to react the mixture with the fatty oil or oils, and thereafter to neutralize the glycerineacid-fatty oil product with caustic soda.

According to the preferred mode of applying the principles of this invention, substantially anhydrous glycerine (around 99.5%) is supplied through a pump II and pipe I2 to the first mixer I3. At the same time fuming sulphuric acid (around 102.8%) is supplied through a pump I 4 and pipe I5 to the same mixer. The pumps II and I4 and a pump for the fatty oil which will be later described are preferably geared together, so that each will supply its respective reactant in exactly the desired proportion. Numerous types of proportioning devices are known and any one of these which is found suitable may be used in place of the pumps shown. As an additional precaution to permit certainty with respect to the proportions of the reactants entering the mixer I3, volometers or owmeters I6 and I'I may be connected to the glycerine pipe I2 and the sulphuric acid pipe I5 respectively, near the point Where the pipes connect to the mixer. Volometers are calibrated vessels arranged to be filled and the time of filling noted by a stop Watch so as to calibrate or adjust the proportioning mechanism. They drain back to the storage tanks after use.

As illustrated in Figs. 5, 7, and 8, the mixer I3 consists of a cylindrical shell I 8, closed at the bottom except for a drain opening I9. 'I'he top of the mixer is closed by a cover 20 upon which is mounted a driving motor 2| and suitable gearing 22, shown in Figure 2. Through the top of the mixer a rotatably mounted vertical shaft 23 dextends, and this shaft is connected to the motor A series of radially extending mixing paddles 24, 25 and 26 are carried by shaft 23 and these paddles are constructed for movement within spaces arranged between hollow annular members 21 and 23 positioned within the cylinder. Cooling water is circulated through the hollow members by means of pipe connections as shown in Fig. 2.

As illustrated, particularly in Figs. 5 and 8, thepaddles and the annular cooling members vary somewhat in form. The four upper cooling members 21 are somewhat smaller in diameter than the inside of the shell I8, and are connected attheir outer edges by cylindrical rings so that a portion of the liquid in the mixer may ilow upwardly from below the fourth member between the wall of the mixer and the peripheries of these upper annular members and thus be mixed thoroughly with the fresh liquid as it enters the mixer. This action is aided by the construction of the paddles in the upper part of the mixer. Each of the three upper paddles 2li consists of a fiat circular plate with four vanes extending .helically above it to throw the liquid outwardly and four helical vanes below the plate to draw the liquid inwardly and propel it downward through the center opening in the underlying cooling element. The flat circular portions of the paddles completely prevent any of the liquid from passing directly downward along the shaft 23. All of the liquid is thus forced to travel out and around the edges of the circular portions of each of those three upper paddles. 'I'he fourth paddle from the upper end is an impeller 25 which must finally be passed by the liquid before it enters the lower part of the mixer. This impeller is of similar construction to the iirst three paddles excepting that the iour vanes above and the four vanes below the plate are all arranged to throw the liquid outwardly and thus force a part of the liquid to return to the top of the mixer and induce a maximum mixing action.

The two lower cooling members 28 are t snugly to the shell by ring members and therefore, all 0f the liquid which passes these members must pass through the openings therein which surround the center shaft 23 and none can pass upwardly around the outside. The paddles 26 lying below the fifth and sixth cooling members are but double radially projecting arms fastened to the shaft 23. A cross member 29 is provided at the bottom of the mixer and this cross member carries a pin 30 which enters an axial opening in the lower end of the shaft 23 to maintain the shaft in alignment. The cross member 29 is further provided with a pair of bafiies 3l which retard any rotation of the liquid in the mixer and direct the liquid through the drain opening i9.

As will appear upon consideration of Figs. 4 and 5, the glycerine and sulphuric acid enter the mixer from pipes i2 and l5 and are released into the mixer at the top and near its center. They progress downwardly through the mixer as they become mixed and the mixture passes out through the drain opening i9. As the glycerine and sulphuric acid are mixed, cooling water is circulated through the cooling members 21 and 28 to keep the temperature sufficiently low to prevent an appreciable darkening of the material. It has been found that a temperature of approximately 30 C. is sufficiently low for this purpose although lower temperatures may be used and somewhat higher temperatures may be permitted without serious results.

Suitable pipes 32 are provided to supply water process of neutralization begins at once.

to the cooling members, the arrangement being such that the cooling water first enters the lower one of the four upper cooling members 21 from which it progresses upward to the top cooling member. It is thereafter conducted to the sixth or bottom cooling member 28,-then to the fth cooling member and finally discharged. This arrangement has been found to be especially desirable because it maintains a fairly even temperature throughout the mixture, the greatest cooling effect being produced in the upper portion of the mixer where-the initial mixing takes place and the tendency for the compounds to react and evolve heat is greatest.

From the bottom of the mixer I3 the glycerinesulphuric acid mixture is conveyed by piping 33 to a second mixer 30 at a point near the top. Fatty oil also enters this second mixer at a point near the top, being supplied by a pump 35 through a pipe 36. The pump, as already explained, is connected so as to supply a quantity of fatty oil accurately proportioned to the amount of glycerine and sulphuric acid supplied by pumps Il and M, respectively. As with the glycerine and sulphuric acid, a volometer or iiowmeter 31 is provided for the fatty oil. This device is connected `to the pipe 36 at a point near the second mixer, so that the proportion of fatty oil entering this mixer can be readily determined.

The construction of the second mixer 34 is substantially the same as that of the first mixer I3, so that it need not be described in detail although it has been shown in Fig. 6j The heat transfer members, which were cooling members in the first mixer, are used as heating members in this.sec ond mixer and hot water is passed therethrough to eiTect the heating. The hot water need not be circulated through the members in the order that the cold water was circulated through the cooling members in the first mixer, but instead the water may first enter the top heating member and then progress downward through the next adjacent members in regular order to the lowest member from which it is discharged.

Furthermore, there are but two of he smaller sized heat transfer members at the top of this second mixer and only one of the paddles has its vanes arranged to throw outwardly above and draw inwardly below the fiat circular portion.

All of the vanes on the second paddle throw outwardly. The lower part of the second mixer includes only heat transfer members fitting closely in the shell and only double bladed radially extending mixing paddles are employed therebetween. Preferably, the average temperature in this mixer is around 50 C.

From the bottom of the second mixer the glycerine-acid-fatty oil reaction product is conveyed to the top of a neutralizer 39 by a transfer line 38. The neutralizer comprises a large cylindrical tank that contains mixing and cooling equipment sufficient to thoroughly mix, at a controlled temperature, the glycerine-acid-fatty oil product with a neutralizing material, which is preferably caustic soda. The caustic enters the upper part of the mixer through a pipe 40 preferably as a solution of 30% to 50% concentration, being discharged into the neutralizer at about the same point as the reaction product so that the two materials pass into immediate confluence and the Upon the admission of the caustic and the reaction product into the neutralizer, the materials ilrst pass downwardly through a cooling cylinder Il and then upwardly between the outside of this f ed on top of the neutralizer.

cylinder and the wall of the neutralizer, which wall forms an additional cooling surface `42. Upon circulating to the upper end of the neutralizer, a part of the product is drawn off through a pipe 43 and conveyed to the drying equipment. The remainder is recycled with the incoming reaction product and caustic solution.

In order to thoroughly mix the caustic solution and the reaction product, agitation is provided in the form of a shaft 44 which extends downwardly through the top of the neutralizer and axially through the center of the inner cooling cylinder 4I. This shaft is driven by an electric motor 45 through suitable gearing all mount- Shaft 44 carries a series of impellers 46 within the inner cooling cylinder and a larger impeller 41 just below the bottom of the inner cooling cylinder 4I for circulating the mixture. Appropriately shaped deflecting members 48 and 49 are provided to direct the mixture onto the large lmpeller member 41 so as to obtain a maximum circulatory effect. In the inner cooling cylinder 4|, there is an axially extending cooling coil 50 which provides additional cooling surface and the cooling water is fed through this coil, into the bottom of the inner cooling cylinder and finally withdrawn from the top of that cylinder.

Between the inner and outer cooling cylinders 4| and 42, are a series of scrapers that continually remove any of the product that solidies upon the cooling surfaces. As shown in Figs. 9 and l0, these Scrapers comprise vertically extending strips 5| and 52 attached to the upright supporting members 55 and 56 and pressed against the inner and outer cooling cylinders, respectively by springs 53 and 54. 'Ihe supporting members are in turn mounted upon a spider 51 carried at the center of the bottom of the neutralizer tank upon a rotatable shaft 58 that extends through the bottom of the tank to suitable driving mechanism 59 and motor 60. 'I'he lower end of the agitator shaft 44 is rotatably received in a cavity in the upper end of this shaft 58. Braces 6I and 62 may be used to join the scraper supporting members 55 and 56, respectively, so as to make a more rigid construction.

In order to control the amount of caustic added, in accordance with the amount necessary to just neutralize the reaction product, a device is connected to the neutralizer for continuously measuring the hydrogen ion potential (pH) of the neutralized product and this device controls an electrically operated valve 63 in the caustic line 40. The measuring device comprises a sampling pipe 64, through which a small amount of the mixed materials is continually withdrawn from a point near the bottom of the inner cooling cylinder by the action of a small pump 65. From the pump the material is discharged into a baille tank 66 in which are electrodes 61 connected to operate the electrically operated valve 63 through an electrometric titration device 68. Thus the amount of caustic supplied is controlled so as to always be just sufficient to neutralize the reaction product, and the neutralized material may be kept accurately at a pH of around 6.0 to 7.0 which has been found highly preferable. The material flowing through the baffle tank is returned to the neutralizer by a pipe 69.

After the product leaves the neutralizer it is preferably conveyed by the pipe 43 to a spray drying device such as shown in Fig. 3 and described in Patent 1,652,900 granted to- Dallas R. Lamont on December 13, 1927. Since this part of the equipment is described in detail in that patent it will be referred -to here only in general terms. 'I'he neutralized reaction product of this invention, together with the considerable amount of water which still remains with it, is sprayed in a fine state of subdivision into a drying chamber 'l0 near the upper end. As it falls it is contacted by a large volume of air forced down through the chamber by suitable pumping mechanism. By the time the product reaches the bottom of the chamber it is dry and in the form of beads. These are drawn off in a current of air into a cyclone separator 1| where they are separated from the air in a form that is ready for packaging.

With the new product there appears to be considerable advantage to spray drying, although, of course, the product may be dried in other ways, if desired. However, if the product is spray dried it forms beautiful, exceptionally White beads that dissolve instantly in water, either hot or cold.

While the apparatus described has been arranged to mix the glycerine and sulphuric acid prior to reacting them with the fatty oil, it is to be understood that this is only the preferred form and that other arrangements may be made. For example, the glycerine, sulphuric acid and fatty oil may all enter one mixer together without any previous mixing or the glycerine and fatty oil may be reacted as originally described in the Acopending application or merely mixed, or the sulphuric acid may be mixed with the fatty oil prior to the addition of the glycerine. Also, lime or other alkaline reagent may be used to effect the neutralization of the product and suitable means provided to settle, filter or centrifuge the product to remove the precipitate formed.

Other features of the preferred apparatus and process, which have been described above, may be modified or omitted without departing from the broader scope of this invention. For example, the construction of the mixers may be changed so that one mixer accomplishes all of the mixing and reacting. Likewise the electrometric titration apparatus may be changed to any desired form, or even eliminated altogether.

I claim:

1. A process of forming a product suitable for use as a domestic detergent that comprises reacting approximately one molecular proportion of fatty oil, two molecular proportions of substantially anhydrous glycerine and an excess over three molecular proportions of fuming sulphuric acid by mixing the sulphuric acid and glycerine and reacting the mixture with the fatty oil, the quantity and strength of the sulphuric acid being such that the concentration of the excess sulphuric acil, after the reaction has been completed, will be in the general neighborhood of 99.3%.

2. A process of forming a product suitable for use as a domestic detergent that comprises reacting approximately one molecular proportion of fatty oil, two molecular proportions of substantially, anhydrous glycerine and an excess over three molecular proportions of around 102.8% sulphuric acid at around normal temperature by mixing the sulphuric acid and glycerine and reacting the mixture with the fatty oil, the quantity of sulphuric acid being such that the excess sulphuric acid, after the reaction has been completed, will have a concentration of around 99.3%.

3. A process of forming a product suitable for use as a domestic detergent that comprises reacting approximately one molecular proportion of fatty oil, two molecular proportions of substantially anhydrous glycerine and an excess over three molecular proportions of fuming sulphuric acid by mixing the glycerine and sulphuric acid and reacting the mixture with the fatty oil and neutralizing the resulting product in the presence of a predominant proportion of already neutralized material, the quantity and strength of the sulphuric acid being such that the concentration of tho excess sulphuric acid, after the reaction has been completed, will be in the general neighborhood of 99.3%.

4. A continuous process of forming a concentrated-solution of a product suitable for use as a domestic detergent that comprises continuously reacting approximately one molecular proportion of fatty oil, two molecular proportions of substantially anhydrous glycerine and an excess over three molecular proportions of sulphuric acid of such quantity and strength that after reaction the excess will still be of at least around 99.3% concentration, by continuously mixing the glycerine and sulphuric acid and continuously reacting the mixture with the fatty oil, and continuously neutralizing the resulting product by continuously passing it into confluence with a concentrated caustic soda solution in the correct proportion for neutralization, in the presence of a predominant proportion of already neutralized material and continuously withdrawing neutralized material from the place of neutralization.

5. A process of forming a product suitable for use as a domestic detergent that comprises reacting approximately one molecular proportion of fatty oil, two molecular proportions of substantially anhydrous glycerine and an excess over three molecular proportions of fuming sulphuric acid and neutralizing the strongly acid reaction products so formed with concentrated alkaline solution, without prior dilution with water, in the presence of a predominant proportion of already neutralized material, by simultaneously adding the undiluted reaction product and concentrated alkaline solution and rapidly mixing them into the already neutralized material thus utilizing the already neutralized material to absorb the heat of reaction and prevent excessive local acid or base concentration or overheating, and maintaining the neutralized material at a temperature not substantially above 50 C.

6. In the process of forming inorganic salts of sulphuric acid esters that are easily decomposed by acidity or basicity in combination with heat, .the step of neutralizing a strongly acid reaction product comprising the aforesaid sulphuric acid esters with concentrated alkaline solution, without prior dilution with water, in the presence of a predominant proportion of already neutralized material, by simultaneously adding the undiluted reaction product and concentrated alkaline solution and rapidly mixing them into the already neutralized material thus utilizing the already neutralized material to absorb the heat of reaction and prevent excessive local acid or base concentration or overheating, and maintaining the neutralized material at a temperature not substantially above 50 C.

'7. In the process of forming sodium salts of sulphuric acid esters that are easily decomposed by acidity or basicity in combination with heat, the step of neutralizing a strongly acid reaction product comprising the aforesaid sulphuric acid esters with concentrated caustic soda solution without prior dilution with Water in the presence of a predominant proportion of already neutralized material, by simultaneously adding the undiluted reaction product and concentrated caustic soda solution and rapidly mixing them into the already neutralized material while utilizing the already neutralized material to absorb the heat of reaction and prevent excessive local acid or base concentration or overheating, and maintaining the neutralized material at a temperature not substantially above 50 C.

8. In the process of forming calcium salts of sulphuric acid esters that are easily decomposed by acidity or basicity in combination with heat, the step of neutralizing a strongly acid reaction product comprising the aforesaid sulphuric acid esters With a lime slurry without prior dilution with water in the presence of a, predominant proportion of already neutralized material, by simultaneously adding the undiluted reaction product and lime slurry and rapidly mixing them into the already neutralized material while utilizing the already neutralized material to absorb the heat of reaction and prevent excessive local acid or base concentration or overheating, and maintaining the neutralized material at a temperature not substantially above 50 C.

9. In the process of forming inorganic salts of sulphuric acid esters that are easily decomposed by acidity or basicity in combination with heat, the step of neutralizing a strongly acid reaction product comprising the aforesaid sulphuric acid esters with concentrated alkaline solution, without prior dilution with water, in the presence of a predominant proportion of already neutralized material, by simultaneously adding the undiluted reaction product and concentrated alkaline solution and rapidly mixing them into the already neutralized material thus utilizing the already neutralized material to absorb the heat of reaction and prevent excessive local acid or base concentration or overheating, and maintaining the neutralized material at a temperature below that at which substantial decomposition of the esterwill occur.

10. A continuous process of forming a product suitable for use as a domestic detergent that comprises reacting approximately one molecular proportion of fatty oil, two molecular proportions of substantially anhydrous glycerine and an excess over three molecular proportions of iuming sulphuric acid, and continuously neutralizing the strongly acid reaction product so formed with concentrated alkaline solution, without prior dilution with water, in the presence of a predominant proportion of already neutralized material, bysimultaneously and continuously adding the undiluted reaction product and concentrated alkaline solution and rapidly mixing them into the already neutralized material thus utilizing the already neutralized material to absorb the heat of reaction and prevent excessive local acid or base concentration or overheating, and maintaining the neutralized material at a temperature not substantially above 50 C., the amount of alkaline solution added being continuously controlled in accordance with the pH of the neutralized material so as to be just sufficient to produce a neutralized material of predetermined pH thus avoiding decomposition due to acidity or basicity of this material.

11. A continuous process for forming a product suitable for use as a domestic detergent that comprises reacting coconut oil, substantially anhydrous glycerine and fuming sulphuric acid containing at least 121/2% sulphur trioxide in approximately the following proportions by weight:

Parts Glycerine 64 Coconut oil 216 Sulphuric acid (calculated as 121/2% oleum) 526 and continuously neutralizing the strongly acid reaction products so formed with concentrated alkaline solution, without prior dilution with water, in the presence of a predominant proportion of already neutralized material, by simultaneously adding the undiluted reaction products and thel concentrated alkaline solution and rapidly 

